P1026s is a Phase IV, prospective pharmacokinetic (PK) study of selected ARV drugs currently used in the clinical care of HIV-infected pregnant women during pregnancy and postpartum. This study is designed to evaluate the following: the pharmacokinetics of antiretroviral medicines when used alone or co-administered with tuberculosis medicines during pregnancy; the pharmacokinetic parameters of lopinavir/ritonavir and atazanavir/ritonavir/tenofovir in women postpartum before and after starting hormonal contraceptives; and the concentrations of ethinyl estradiol, etonogestrel and other progestins in women using hormonal contraceptives and protease inhibitors.

Main Objectives:

To describe the pharmacokinetic parameters during pregnancy of selected ARV drugs currently used in the clinical care of HIV-infected pregnant women, and to compare these parameters to a) historical pharmacokinetic data from non-pregnant adults and b) postpartum pharmacokinetic data from the same women in the study cohorts.

To describe the pharmacokinetic parameters during pregnancy and postpartum of selected ARV drugs (efavirenz, nevirapine, lopinavir/ritonavir) and TB drugs (ethambutol, isoniazid, pyrazinamide, rifampicin) when co-administered as part of clinical care of HIV-infected pregnant women and of the selected TB drugs when used in HIV-uninfected pregnant women.

To describe the pharmacokinetic parameters of lopinavir/ritonavir and atazanavir/ritonavir/tenofovir in postpartum women before and after starting hormonal contraceptives.

To describe the concentrations of ethinyl estradiol, etonogestrel and other progestins in women using hormonal contraceptives and protease inhibitors as compared to historical controls not using protease inhibitors.